This mindhack illustrates the power of conditioning the mind to perform mathematical operations.

This was excerpted from the IJMC website:
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FOLLOW these instructions one at a time and as QUICKLY as you can!

What is:

2+2?

4+4?

8+8?

16+16?

Quick! Pick a number between 12 and 5. Got it?

Now scroll down...

The number you picked was 7 right?
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One explanation for the success of this mindhack is that the mind is gradually conditioned to immediately add up any two numbers it is given. The last question asks for a number between 12 and 5, so the mind adds up to 17, but realizes that it is larger than 12. 17 is now the most recent number in the mind, and the sense of urgency to pick a number means that 7 is also readily available, and greater than 5.